Design of a compact beam dump for the BNL--AGS neutral beam

BNL-E871 is a two arm rare kaon decay spectrometer at the BNL-AGS. The experiment uses a neutral kaon beam to search for the forbidden decay KL0 → μe. The previous experiment in the same beam line allowed the neutral beam to pass through a gap in the spectrometer. For E871 it seems more advantageous to dispose of the beam in a compact beam dump located in the middle of the spectrometer. The elimination of the beam allows increase in acceptance by eliminating the gap in the downstream spectrometer, reduces accidentals in the trigger, and in the downstream particle identification detectors